Neurobehavioral effects of postnatal exposure to low-level mercury vapor and/or methylmercury in mice

• Yoshida Minoru

  Faculty of Health and Medical Care, Hachinohe Gakuin University

• Lee Jin-Yong

  Laboratory of Pharmaceutical Health Sciences, School of Pharmacy, Aichi Gakuin University

• Satoh Masahiko

  Laboratory of Pharmaceutical Health Sciences, School of Pharmacy, Aichi Gakuin University

• Watanabe Chiho

  Department of Human Ecology, Graduate School of Medicine, University of Tokyo

Abstract

This study examined the effects on neurobehavioral function of exposure to low-level mercury vapor (Hg⁰), methylmercury (MeHg) in female mice and the combination of Hg⁰ and MeHg during postnatal development. Postnatal mice were exposed to Hg⁰ at a mean concentration of 0.188 mg/m³ Hg⁰ and supplied with food containing 3.85 μg/g of MeHg from day 2 to day 28 after delivery. The combined exposure group was exposed to both Hg⁰ and MeHg, using the same procedure. When their offspring reached the age of 11 weeks, behavioral analyses were performed. The behavioral effects in mice were evaluated based on locomotive activity and rate of center entries in the open field (OPF), learning activity in the passive avoidance response (PA) and spatial learning ability in the radial maze (RM). Total locomotive activity in the OPF significantly decreased in the Hg⁰, MeHg and combined exposure groups compared with the control group. The proportion of entries to central area in the OPF was significantly higher in the combined exposure group than in the control group, while those in the Hg⁰ or MeHg exposure group did not differ from the control group. Other behavioral tests did not reveal significant differences among the groups. Behavioral anomalies were more distinctive after combined exposure compared to Hg⁰ or MeHg exposure alone. The brain Hg concentration of offspring, immediately after exposure, was highest in the combined exposure group, exceeding 2 μg/g, followed by the MeHg and Hg⁰ exposure groups. Thus, the enhancement of neurobehavioral effects in the combined exposure group was associated with higher brain mercury concentration.

Journal

• The Journal of Toxicological Sciences

  The Journal of Toxicological Sciences 43 (1), 11-17, 2018

  The Japanese Society of Toxicology

Keywords

• Mercury vapor
• Methylmercury
• Combined exposure
• Behavioral toxicity
• Offspring mice

Details

• CRID: 1390282679881457280
• NII Article ID: 130006338342
• NII Book ID: AN00002808
• DOI: 10.2131/jts.43.11
• ISSN: 18803989
• ISSN: 03881350
• NDL BIB ID: 029026466
• PubMed: 29415947
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I029026466
• Web Site: https://www.jstage.jst.go.jp/article/jts/43/1/43_11/_pdf
• Text Lang: en
• Data Source:
  • JaLC
  • NDL
  • Crossref
  • PubMed
  • CiNii Articles
  • KAKEN
• Abstract License Flag: Disallowed